Delete more than 10000 records using script without limit in Salesforce Apex

Better to use Data Loader for such scenario.

Even if you have to Delete it using Apex script with some custom logic, I would recommend you to add records to collection and break it at 9990 and then create another instance of collection to update. You can write automated logic to break the collection based on the size and perform DML on them.

Write a batch class to delete the records.

Two ways of Executing the batch class :

1. Execute it in "Anonymous" block or
2. Create a VF page with a Delete button which invokes the batch class(with VF page you can catch the errors while performing delete operation and can show it on VF page as error messages)

Use batch class

Hello,

it will work just fine. You can even write it in 1 line:

delete [Select Id from sObject where Test__c = true Limit 9000];
It will fail the whole delete operation though if there's any kind of problem (like "before delete" trigger that makes some extra checks and complains). You can set it to "delete what you can, I'll deal with errors separately" by using another version of delete that takes an extra parameter.

Database.delete([Select Id from sObject where Test__c = true Limit 9000], false);

Thanks.